The chemical name of cyclophosphamide is 2-[bis(2-chloroethyl)amino]tetrahydro-2H-1,3,2-oxazaphosphorine 2-oxide monohydrate. The compound along with related novel cyclic phosphoric acid ester amides was disclosed and claimed in U.S. Pat. No. 3,018,302. Cyclophosphamide, an anti neoplastic agent classified as an alkylating agent.
Cyclophosphamide is a prodrug, converted in the liver to active forms that have slow down the growth of cancer cells and requires enzymatic and chemical activation to produces active form. Cyclophosphamide is used alone or in combination with other drugs to treat various cancers like metastatic breast cancer, ovarian cancer, and leukemia. When given by orally, cyclophosphamide shows superior efficacy than when it is given intravenously.
U.S. Pat. No. 5,047,246 discloses directly compressible pharmaceutical composition comprising cyclophosphamide and a partially or fully pregelatinized starch. The pharmaceutical composition, when directly compressed into a tablet, exhibits unexpected stability when compared to cyclophosphamide in combination with other direct compression vehicles.
U.S. Patent publication no 20010046504 discloses film-coated tablets with cyclophosphamide as active compound, which in the core comprise cyclophosphamide, one or more fillers, one or more dry binders (but no preswollen starch), flow regulators and lubricants.
The above prior-art discloses that direct compression is desirable method for cyclophosphamide tablet. Further, the U.S. Pat. No. 5,047,246 discloses that wet granulation method has certain drawback, from which one of the problem is dissolution rate of the tablet varies from batch to batch, with some batches having unacceptably low rates.
This problem may arise due to a combination of factors such as non-ideal granule characteristics such as particle size of active pharmaceutical ingredients, particle size differences with excipients, and segregation during manufacturing operations. Further ensuring content uniformity is a pretty significant parameter for efficiency of the treatment. In other terms, dose of an active agent which is required to be contained in a capsule or a tablet in order to provide therapeutic effect is closely related to flow characteristics of the formulation comprising said active agent.
Content uniformity of mixture is said to be achieved when the proportion and particle size of the ingredients is identical all over the mixture. Particle size of active ingredient also plays an important role in achieving content uniformity.
Several products of pharmaceuticals are a blend of various powders or bulk solids. Hence mixing of powders is a very important part of pharmaceutical product development. Further for pharmaceutical formulations there are currently three basics methods used for the product development to increase dissolution rate, flowability, density of API, better distribution of API for low dose formulations. They are the wet granulation method, the dry granulation method and the direct compression method
Therefore there is great interest in the industry to understand the interplay of various granule characteristics such as particle size of active pharmaceutical ingredients, particle size distribution and granule loading with tablet content uniformity. Unfortunately, cyclophosphamide is one of the few known compounds which possess the above problems.
However, there is still an existing and continual need to overcome the above mentioned problems. The inventors of the present invention address the need of sufficient flow characteristics and content uniformity by provide a pharmaceutical composition of cyclophosphamide alone and/or in combination with other pharmaceutical active ingredients wherein the cyclophosphamide particles has D90 particle size less than 100 microns.